The extensive alterations in tissue morphology, cellular biochemistry and regulation of gene expression that culminate in the genesis of the midface result from the interaction of multiple hormone- and growth factor-activated signaling pathways. Little attention has been focused on characterization of these pathways and the nuclear events responsible for transducing short-term cellular signals into long-term phenotypic alterations associated with normal orofacial development. This application investigates 1) the role of the signal transducer protein kinase C in mediating the effects of various palatal hormones and growth factors and 2) the role of 'early response' nuclear oncogene families in protein kinase-mediated signal transduction during growth and differentiation of the mammalian secondary palate.